Girls' Heart Events
To get married you must first raise the heart level of a girl. There are seven Hearts to go through: Black, Purple, Blue, Green, Yellow, Orange, and Red. Below are the girls, their heart events, and how/where/when to get them!!
note: time between events does differ between girls and players. I was married by fall, year 2. My friend however, married in year 3.

Karen
Black Heart Event- When you first begin your game, you'll need to go to the store to buy some seeds, on a Wednesday or Friday head to the store at 10:00am - 1:00pm. Keep an opened slot since she gives you a pack of Grass seeds. Just in case.
Purple Heart Event - It's during the day whenever the shop's opened in the morning. Not on Tuesdays or Wednesdays. Has been triggered on a saturday, sunny, at 10:00am. A decision one of course.
Blue Heart Event - Well, this one occurs between 10am - 1pm on a Friday, head to the grocery store and you'll be given decisions
*Green Heart Event - when Karen's heart is green,you go to the Inn on sunday at 7:00pm - 10:00pm, to trigger this. May or may not raise heart level
Yellow Heart Event - Go to the superstore between 10:00am to 1:00pm, Monday,Tuesday, or a Saturday. You'll receive another decision making event which I'm sure you'll know which one to pick. Places to meet: Mondays, Wednesdays, Thursdays, Fridays, Saturdays - 8:00am - 10:00pm, bench up north with Rick. 1:00pm - 3:00pm, inside the store, this is usually the best time to talk to her and give her a present. 7:00pm - 10:00pm, she'll head to the beach. For Tuesdays, she'll be at the springs in 1:00pm - 3:00pm, at the Bar at 7:00pm - 10:00pm. Sundays she'll be at the bar ONLY at 7:00pm - 10:00pm. On rainy days, she'll be inside at the times given in the superstore. Tuesdays though she'll be at Gotz's house, Sundays, no change.
Items: Bamboo shoots, which grows in the lake area next to the winter mine, is the cheapest and she likes it a lot. Took me only 10 days giving her a bamboo shoot once a day, wrapped most of the time to get her heart to purple. Wine and popcorn are nice ones too. Buy wine from the winery shop. Extra love point if you buy at least one item from the shop.
Rival: Popuri's brother, Rick.

Ann
Black Heart Event - Triggered this at the beginning, on a Friday, raining, (NOTE) Rain probably has nothing to do with. Around 10:00am - 1:00pm?
Purple Heart Event - This is a decision making one that's triggered when your on the second floor of the Inn between 10:00am and 1:00pm on a Wednesday, Thursday, Friday, or Saturday. Triggered this on a Thursday 12:20pm. Sunny.
Blue Heart Event - Trigger this by heading to the Inn on Mondays or Fridays around lunch time to 7:00pm. This is another decision making.
Yellow Heart Event - Triggered around 10:00am to 7:00pm on Wednesday, Thursday, Saturday, or Sunday.
Places to meet: Usually most of the time she's at the Inn either upstairs or downstairs at around lunch time and such so it's easy to find her. In the mornings she can be found at the Hot Springs.
Items: She loves any egg dishes (scrambled, spa boiled, etc.) The best things she likes are Truffle Rice, Cakes, and Cheese Fondu. Extra love point if you buy at least one item from her dad's bar. Water works too.
NOTE:You can jack her heart up to the next color if you trigger the Cliff's Photo Event. Around 11:00am - 1:00pm(I think that's the limit but it starts at 11:00am, go to the square BUT ENTER IT FROM THE SOUTH, like, go through yodel farm and head north into the Square, then you'll trigger it, but it only triggers if it's a winter and it's snowing. Once you pick up the photo, give it to cliff and you'll get his story on why he's so messed up. Talk to Ann and her heart should be at the next level.
Rival: Cliff

**Popuri
**=my wife
Black Heart Event - It has to be sunny, and around 4:50pm. So maybe 2:00pm to 5:00pm. I simply walked into onto the street and it triggered it but you may need to go into a shop and come out (like the blacksmiths or something). EDIT: 11:00am - 6:00pm, it's strange to trigger so just enter the blacksmith and out.
Purple Heart Event - This is triggered when her heart is purple, just...well... it'll happen, no need to go around and look for the trigger, you just need her heart at a purple level. So give her gifts!!
Blue Heart Event - Triggered around 10:00am to 1:00pm at the Church.
Yellow Heart Event - Triggered in the Spring season around 10:00am to 1:00pm at the chicken farm. This would have to occur in the 2nd year, unless you can get her heart to yellow ASAP. It has been said to be done in winter but I think this occurs mainly in spring.
Places to meet: Mainly at the chicken farm when it's opened.
Items: Scrambled eggs(all eggs will do. I brought her 3 spa boiled eggs each day by the hot springs). Extra love point if you get 8 chickens from her farm.
Rival: Kai (only comes in the summer so you have the advantage)

Mary
Black Heart Event - .Go to the library on aTuesday around 9:00am - 3:00pm, or at least when the library is opened, not on mondays because it's closed on that day.
Purple Heart Event - Triggered at the library around 10:00am to 4:00pm on Thursday, Saturday, or Sunday.
Blue Heart Event - Triggered at the mountain peak at Mother's Hill between 1:00pm - 5:00pm on Monday, sunny, and need an opened slot in your item.
Yellow Heart Event - Mary's house will trigger this between 10:00am to 1:00pm on Monday since the Library is closed that day
Places to Meet: Library pretty much everyday and on mondays she's at the grocery store at 1:00pm.
Items: Grass, grape juice Extra love point if you go upstairs in the library.
Rival: Grey, the blacksmith assistant

Elli
Black Heart Event - Beginning of the game you can trigger this, go to the doc's office at around 9:00am - 3:00pm. Don't do it on a wednesday since that's when it's closed
Purple Heart Event - Triggered by heading to the Hospital around 9:00am to 7:00pm on Thursday, Saturday, or Sunday.
Blue Heart Event - Triggered on Wednesday when the doc's office is closed between 9:00am to 1:00pm. NOTE: Ok GO TO Elli's house, it's not the church.
Yellow Heart Event - Trigger this at Mineral Beach between 9:00am to 6:00pm on Wednesday, head to the dock.
Places to meet: Though she's mostly at the hospital, you can meet her at the grocery store on Wednesdays at 1:00pm.
Items: Milk, grass, pink cat flower
Extra love point by coming in on a daily basis to get a check-up by the doc.
Rival: The Doctor

Goddess
Ok, the Goddess is hard.She has no rival whatsoever and when you marry her, she doesn't wanna live with you anyways. Though if you want her, she's at the waterfall(lake) next to the hot springs. Throw in a crop to summon her. You need to fish all species of fishes including the 6 kings. Ship at least one of every shippable item, collect all 9 Jewel of Truth, Big Bed, Mine every type of ore in the mines, and be in your 5th year or later at the farm.
Note: However, throw a crop once every day for 10 days straight, you will get a power berry. Another 11 times she'll grant you a wish and ask you who you like. Select the girl you like and she'll raise her heart level. Very useful.